Batteries – Helpful Hints

Even when a battery is disconnected and sits for several months, it loses power by self-discharge.

Check voltage: With all the power off and the battery disconnected, check the voltage level. Readings of 12.70 – 12.80 volts or higher mean the battery should be close to or at full charge. If it is below 12.60 volts, it needs to be charged. A battery at 12.75 volts is about 50% and below 12 volts is 100% discharged.

Make sure connections are clean: Your batteries may look good, but oxidation can attack where you can’t see. Anything that comes between your battery’s terminals and your engine’s cables needs to be cleaned off. Baking soda and water work well to neutralize acid. Use distilled water to clean and use a terminal protector spray.

Water level: Skip this step if you have a sealed or absorbed glass mat (AGM) battery. With flooded or wet cell batteries, remove the vent caps and check electrolyte levels. If the level is below the plates, refill with distilled water until the plates are covered – about half inch. Do not overfill – max level is about a quarter inch below the vent well.

Recharge: Make sure the charger you’re using is designed for the type of battery you have. The following chart offers general guidelines:

HOW LONG TO CHARGE YOUR BATTERYApproximate charge time (in hours) for batteries at or below 12.35 Volts.